Windshield wash water heater

ABSTRACT

For inclusion on the line between the wash liquid supply and the discharge jets of an automotive vehicle windshield wash liquid pumping system, a liquid heater secured on the engine exhaust pipe, comprising a pipe-embracing saddle-shaped metal body with a cavity forming a liquid heating flow space provided with line connector nipples.

United States Patent 1191 1111 3,785,359 Whittaker Jan. 15, 1974 154]WINDSHIELD WASH WATER HEATER 3,148,675 9/1964 Menuto 126 195 [76]lnventor: Thomas H. h ttaker, 14 o de 1,651,875 12/1927 Ercanbrack165/176 Elght Northfield Ohlo 44167 Primary ExaminerEdward G. Favors[22] Filed: Mar. 28, 1970 Attorney-Philip D. Golrick [21] App]. No.:238,850

[57] ABSTRACT [52] us. c1. 126/195 For inclusion the line between theWash liquid 511 1111.0. F24b 1/00 P and the discharge Jets of autommiveVehicle [58] Field of Search 126/19.5; 237/12 Windshield Wash liquidPumping System, a liquid heater secured on the engine exhaust pipe,comprising 5 References Cited a pipe-embracing saddle-shaped metal bodywith 21 UNITED STATES PATENTS cavity forming a liquid heating flow spaceprovided with line connector nipples. 2,467,156 4/1949 Sala 126/195 X1,757,448 5/1960 Cooper 126/195 5 Claims, 4 Drawing Figures WINDSHIELDWASH WATER HEATER By common winter experience of auto drivers much onthe road, especially in the more northernly regions of the United Statesand Canada, frosting, icing or the like of the windshield is often anannoyance and not infrequently a definite driving hazard. Thus where avehicle has been parked out of doors, freezing rain, sleet, or wet snowwhich has frozen, or at time heavy frost, may be deposited which is notremovable by windshield wiper action, may in fact have immobilized theblades, but in any event requiring scraping or chipping or applicationof chemical sprays, or a prolonged wait for the defrosters to melt orlessen the deposit, to clear at least the wiper-swept area, before thevehicle can be safely driven.

Even under some warm weather driving conditions, hot wash water becomeshighly desirable. Thus road oil or grime, especially on a recentlywetted road, thrown against the windshield, can be cleaned in a secondor two with heated wash water, whereas with unheated wash there may beseveral seconds of dangerously obscured vision. Also vehicles parkedunder certain species of trees will accumulate a sap-like deposit whichis not easily washed off by the usual auto windshield washers.

At times, even when a vehicle is being driven with the defrosters on atfull heat and wipers operating, severe weather conditions may lead tosome vision-obscurring icing, or there may be a small localized pad ofice or snow frozen onto a blade and spacing the rest of the blade fromeffective glass-wiping contact, so that vision is interfered with unlessthe driver stops to clean the blade. Usually under these circumstancesthe windshield washer system is of little help, since its wash liquidsupply is itself comparatively cold and in any event would requireundesirably extended use to be of any value.

To overcome such conditions, hitherto there have been under -the-hoodapparatus or systems proposed to heat a suitable aqueous liquid by heatexchangers picking up heat either from the exhaust manifold or exhaustpipe, or from heated engine coolant, with the heated water then directedonto the windshield as needed.

The prior proposals have entailed various disadvantages. Some forexample have by-passed or diverted exhaust gasesthrough the heatexchanger, undesirable since interrupting the integrity of the poisonousexhaust gas conduits. Others have required connections into the engineblock, the coolant hoses or inside heater hoses to furnish a heatingmedium to the wash water heater. Both types have had a degree ofcomplexity in structure and/or in mounting which preferably is avoidedor minimized.

By. the present invention there is provided a heater for the windshieldwash water which is readily clamped and secured on an exhaust pipe ormanifold to pick up waste heat, and without penetrationor interruptionof the exhaust gas conduits, and which is simply connected into thewindshield washer system. Further the heater structure itself is quitesimple, maintence-free and of comparatively low cost, involving only asimple body, such as a casting, a clamping device, and only a pair ofsimple line connector fittings in the preferred form hereinafterdescribed in detail.

The general object of the present invention is to provide a simple lowcost rugged heat exchanger unit for 2 heating a liquid by engine exhaustwaste heat in an automotive vehicle.

Another object is to provide a simple windshield wash liquid heaterreadily installed in a vehicle such as an automobile.

Another object is to provide a heater furnishing heated water forcleaning a windshield of icing in conjunction with wiper action over itsarea in a comparatively short time after engine starting.

Other objects and advantages will appear from the following descriptionand the drawings wherein:

FIG. 1 is a schematic diagram of a heater installation in a windshieldwiper wash water system;

FIG. 2 is a perspective view of a heat exchanger unit mounted on afragmentarily shown engine exhaust pipe;

FIG. 3 is a horizontal section taken as indicated by the line 3-3 inFIG. 2; and

FIG. 4 is a section similar to FIG. 3 in a modification.

In the drawings, FIG. 1 schematically represents use of a heater unit Hof the invention as hereinafter described in an automotive vehicleenvironment, namely in a windshield washer system, wherein the washerjets J are supplied with heated water through lines 10-11 by pump P withintake connected by line 12, the heater H and heater inlet line 13 tothe wash water liquid supply vessel S. The heater is held in thermallyconductive contact and heat transferring proximity with the engineexhaust manifold or the exhaust pipe X to warm the wash water passingtherethrough.

The heater unit H, in general form of uniform section along its lengthand symmetrical about a longitudinal center plane, has a longitudinallystraight transversely concave bottom recess 15a and a transverselyarcuate top 15b merging into straight nearly parallel outer sidesurfaces defining narrow bottomed side skirts 15c; providing top andside surfaces well adapted for band clamping on the cylindrical pipeexterior as shown in FIG. 2, by even a simple bolt-tightened clamp strapC or any other suitable banding clamp, with the opposed band ends at 16bolted on or near the flat skirt region.

The basic heater structurecomprises a body block element 20, e.g., analuminum casting, providing some capacity as a heat sink and waterpassage space through the walls of which heat from the engine exhaustpipe X is absorbed by the water; the element 20 having parallellongitudinal blind passages or bores 21, 22, the mouths of which at oneflat end face are closed by a preferrably matching end plate 23 sealedthereto by a suitable gasket 24, and secured by screws or bolts 25. Theblind bores are connected by a slot 26 joining the passage mouths at theend face to define a water flow hollow or space in the heater, from oneto the other of the connector fittings 27, 28 screwed into threadedapertures in the integral end wall of the casting to open to th passageends.

The outer ends of the fittings 27, 28 afford here circumferentiallyribbed nipples adapted to accept and hold thereon the ends of theelastomeric tubing used in the typical auto windshield washer systembetween supply container S and the inlet of pump P. Gasket 24 may be asimple soft fiber or resilient sheet material having the same section asthe casting 20. Also the block 20 may as cast have apertures to besubsequently threaded for the bolts 25, and for fittings 27, 28, sincethese are not crucially located; especially where the bolt holes in 23are made oversize. Similarly'the passages 21, 22 and slot 26 rather thanby drilling or other machining preferrably are simply formed as cast, asmay be also easily be done to provide at least the nipple projections atthe locations of inlet and outlet fittings 27, 28 for subsequentdrilling.

In place of the parallel passages 21, 22 providing the back and frontpassage of FIG. 2, in FIG. 4 a wide flat slot-like cavity 21a is formedin the body element 20a as cast, with one fitting 28 then preferablylocated in the end plate 23 in the region where it closes the slot end.

Where it is desired to make the block element with the longitudinalhollow formed therein as an extrusion, then in place of the integral endwall of the FIG. 3 or FIG. 4, for example, a second end plate would beused bolted and gasketed to the second end; as may also be done witheither a casting or extrusion when more than two liquid passes aredesired with a connecting slot at each end.

Plate 23 in either case may be a stamping punched out of sheet stock tothe required outline and provided with the necessary holes for the boltsand in the case of FIG. 4 for the fitting 28. i

The convexity of the recess a may amount to almost a full semi-cylinder,preferrably with slight straight and diverging wall portions for easierplacement, also casting draft; and where pipe X has the same curvature arather extended heater-to-pipe contact area is then obtained. However,even where the pipe radius is say smaller, so that theoretically a linecontact would result, practically a more than line contact arises andwith, moreover, the embracing of the pipe by the dependent struts, theproximity still offers further good heat transfer by radiation and airconvection to the extent that one heater size may usefully be appliedeven to a range of pipes.

It is seen that a simple structure for a wash water heater unit isprovided readily produced by low cost fabrication operations, basicallyone-piece, two-piece or at most three-piece in form, and well adaptedfor simple secure clamping, even by a wrap-around strap style clamp,though the body may be provided with points for clamp attachment.

It has been found that a heater unit of the structure appearing in FIG.1 with elements'20 and 23 cast aluminum, weighing about 17 ounces, 2 /8inches long, 2 inches high, 3 Mi inches wide, and with a bottom recessmouth span of 3 A; inches, was suitable for the intended purposes on theexhaust pipes in a wide variety of current model compact and standardsize automobiles.

I claim:

1. For heating a wash liquid, used in an automotive vehicle forwindshield washing, by waste heat available at an internal combustionengine exhaust system having an exhaust gas conducting pipe, a liquidheater comprising a cast metal body having a longitudinal transverselyconcave bottom recess for saddling a vehicle engine exhaust system pipein thermally conductive contact,

a transversely convex top merging downwardly into parallel longitudinalside skirts, laterally defining downwardly extended walls of saidrecess;

said body having therein a liquid conducting passageway with endsopening through the external surface of the body to provide inlet andoutlet openings for said passageways; and a pair of external connectorfittings assembled to respective said openings of said body providingwash liquid inlet and outlet line connections to said passageway, forconnection of the heater to a source of wash liquid and for a connectiondischarging to windshield wash jets.

2. A heater as described in claim 1, wherein said body is a casting withsaid passageway provided by at least two parallel longitudinal cast-inpassages laterally connected to each other at one end of said body by ajoining passage, and said fittings are threaded into respective saidopenings.

3. A heater as described in claim 1, wherein said body is a casting withsaid passageway cast therein and provided by a plurality oflongitudinally extending cast-in passages connected in series by alateral cast-in joining passage at a respective end,

said fittings being threaded into respective openings of the castinginto ends of the cavities providing respective ends of the series.

4. A heater as described in claim 1, and

means clamping said body saddled on a pipe conducting hot exhaust gasesfrom the vehicle engine.

5. A heater as described in claim 1, comprising:

said body as including a block element having a said longitudinal bottomrecess, and an end plate element;

said block element having a longitudinal hollow opening through at leastone generally flat body end face at one end of the block element;

said end plate bolted to said end face as a closure element for saidhollow at said one end to define a liquid flow space, the body beingclosed at the other end; gasket means sealing said end plate to the bodyblock element; and

said pair of external connector fittings secured in the assembly of saidelements to open to said hollow as said passageway.

1. For heating a wash liquid, used in an automotive vehicle forwindshield washing, by waste heat available at an internal combustionengine exhaust system having an exhaust gas conducting pipe, a liquidheater comprising: a cast metal body having a longitudinal transverselyconcave bottom recess for saddling a vehicle engine exhaust system pipein thermally conductive contact, a transversely convex top mergingdownwardly into parallel longitudinal side skirts, laterally definingdownwardly extended walls of said recess; said body having therein aliquid conducting passageway with ends opening through the externalsurface of the body to provide inlet and outlet openings for saidpassageways; and a pair of external connector fittings assembled torespective said openings of said body providing wash liquid inlet andoutlet line connections to said passageway, for connection of the heaterto a source of wash liquid and for a connection discharging towindshield wash jets.
 2. A heater as described in claim 1, wherein saidbody is a casting with said passageway provided by at least two parallellongitudinal cast-in passages laterally connected to each other at oneend of said body by a joining passage, and said fittings are threadedinto respective said openings.
 3. A heater as described in claim 1,wherein said body is a casting with said passageway cast therein andprovided by a plurality of longitudinally extending cast-in passagesconnected in series by a lateral cast-in joining passage at a respectiveend, said fittings being threaded into respective openings of thecasting into ends of the cavities providing respective ends of theseries.
 4. A heater as described in claim 1, and means clamping saidbody saddled on a pipe conducting hot exhaust gases froM the vehicleengine.
 5. A heater as described in claim 1, comprising: said body asincluding a block element having a said longitudinal bottom recess, andan end plate element; said block element having a longitudinal hollowopening through at least one generally flat body end face at one end ofthe block element; said end plate bolted to said end face as a closureelement for said hollow at said one end to define a liquid flow space,the body being closed at the other end; gasket means sealing said endplate to the body block element; and said pair of external connectorfittings secured in the assembly of said elements to open to said hollowas said passageway.